Shutter mechanism for cameras



Dec. 13, 1960 R. R. WAREHAM 2,963,951

SHUTTER MECHANISM FOR CAMERAS Original Filed April 29, 1955 4 Sheets-Sheet 1 I06 lflNVENTOR sviwm ATTORNEYS Dec. 13, 1960 R. R. WAREHAM 2,963,951

SHUTTER MECHANISM FOR CAMERAS Original Filed April 29, 1955 4 Sheets-Sheet 2 INVENTOR ZLWMW/ ATTORNEYS Dec. 13, 1960 R. R. WAREHAM 2,963,951

SHUTTER MECHANISM FOR CAMERAS Original Filed April 29, 1955 4 Sheets-Sheet 3 ATTORNEYS Dec. 13, 1960 R. R. WAREHAM 2,963,951

SHUTTER MECHANISM FOR CAMERAS Original Filed April 29, 1955 4 Sheets-Sheet 4 INVENTOR BYJLWM ATTORNEYS United SHUTTER MECHANISM' FOR CAMERAS Richard R. Wareham, Marhlehead, Mass, assignor to Polaroid Corporation, Cambridge, Mass, a corporation of Delaware 12 Claims. (Cl. 95-60) This invention relates to photography and, more particularly, to novel shutter mechanism.

The present application is a division of copending application Serial No. 504,757, filed April 29, 1955, now US. Patent No. 2,878,736.

Objects of the present invention are to provide, in a camera shutter, a disc-type shutter blade, a cover blind coaxially mounted with the shutter blade, means for pivoting the shutter blade into cocked position, said cover blind including means for engaging and pivoting said shutter blade into cocked position during cocking movement of said cover blind, and means for causing said cover blind to release said shutter blade for operation when the latter is in cocked position; and to provide a cover blind of the above type mounted for both linear and pivotal movement.

*Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

Figure 1 is an exploded view illustrating in perspective the elements of a shutter embodying the present invention;

Fig. 2 is a front plan view of the shutter of Fig. 1 illustrated at the position of rest with the time latch in instantaneous position;

Fig. 3 is a section taken along the line 3-3 of Fig. 2;

Fig. 4 is a section taken along the line 4-4 of Fig. 2;

Fig. 5 is a plan view similar to that of Fig. 2 and illustrating the elements of the shutter at the instant of release; and

Fig. 6 is a plan view similar to that of Fig. 5 taken an instant after release of the shutter with the shutter blade shown retained in bulb exposure position.

Generally, the present invention comprehends the provision of a shutter which is relatively simple and inexpensive in construction and capable of being set for a plurality of accurately predetermined shutter speeds. Shutter speed, as referred to herein, is to be regarded in terms of an exposure period during which light passes through the lens aperture. The shutter includes a pivotable shutter blade having therein a plurality of arcuate slots and a cover blind. The shutter blade is pivotable from a position of rest, with one of the arcuate slots positioned at one side of the lens aperture, to a cocked position, with said one slot positioned adjacent the other side of the lens aperture. The cover blind covers the States Patent tee lens aperture as said one slot moves across said aperture during pivotal movement of the shutter blade into cocked position, and is positioned to one side of the lens aperture during the return movement of the shutter blade as the slot passes across and uncovers the lens aperture. The exposure period is determined by the length of the slot and the speed of movement of the slot across the lens aperture. The shutter is adapted to incorporation with any of a variety of conventional cameras and is particularly suitable for use in cameras employing lenses of fixed focus and small relative aperture which are adapted to exposure of films having a fast emulsion. A rotatable disc-type diaphragm having a plurality of apertures of predetermined diameter is directly coupled with the shutter blade for controlling the shutter speed setting. This disc-type diaphragm permits formation therein of small apertures of exact light-admitting properties and is provided with indicia such as numbers for indicating the setting for particular combinations of shutter speed and aperture diameter. I

Referring now to the drawings wherein like numerals denote like parts, there is shown in Figs. 1 through 5 a shutter mechanism, comprehended by the present inventiomthe associated elements of which are represented in Figs. 2 and 5 as they would appear from a position in front of the camera. Directions of the rotation and movement of the elements as hereinafter described are those which would be observed when said elements are viewed from the above described position, the descriptive language being in accordance with said point of observation.

As a means for enclosing and mounting the operative elements of the shutter'mechanism, there is provided a generally rectangular housing 10 including a front portion 12, shown as mounting a conventional lens 14, and a rear portion 16 having a lens aperture 18 in alignment with the axis of lens 14. Front and rear portions 12 and 16 include relatively short side walls, the side Walls of front portion 14 extending exteriorly of the side walls of rear porton 16 to aid in preventing the leakage of light through aperture 18.

An aperture control means is provided in association with lens aperture 18, said means comprising a disc-type diaphragm 20. Diaphragm 20 includes a central dished or recessed section 22, a plurality of evenly spaced exposure apertures 24 having predetermined diameters and a hole 26 at its center at which disc 20 is pivotally mounted to permit movement of any of apertures 24 into operative alignment with lens aperture 18. A short post or shaft 28 is secured in rear portion 16 and extends forward for pivotally mounting diaphragm 24 at hole 26 together with other elements of the shutter assembly. So that disc 20 may be rotated for bringing any particular aperture 24 into alignment with lens aperture 18, disc 20 is so mounted that a portion of its periphery extends through a slot in the side wall of housing 10 exteriorly of the housing and is manually engageable for pivoting the diaphragm. In order to hold an aperture 24 of disc 20 in operatively aligned position, disc 20 is provided with a plurality of evenly spaced V-shaped notches 30 around its periphery, there being provided one notch for each aperture 24. A bracket '32 is secured to rear portion 16 for mounting an elongated detent spring 34 having one end portion 36 adapted to engage notches 30 so as to permit the rotation of disc 20 in only a counterclockwise direction and to retain disc 20 with any selected aperture 24 in alignment with lens aperture 18.

To control the passage of light through lens aperture 18 of the shutter, there is provided a shutter blade comprising a generally flat disc 38 having therein a plurality of predeterminedly spaced arcuate slots 40 of varying lengths. Shutter discs 38 includes a round opening 42 at its center at which shutter disc 38 is pivotally mounted adjacent diaphragm on a hub 44 mounted on post 28. Shutter disc 38 is so mounted on hub 44 that slots 40 are movable in alignment with and across lens aperture 18 in order to uncover said aperture, the duration of the exposure effected thereby being proportional to the length of the slot crossing the lens aperture.

Shutter disc 38 is normally biased in a clockwise direction by a torsion spring 46 coiled around post 28 and positioned between shutter disc 38 and diaphragm disc 20 in dished section 22 of disc 20. Spring 46 is anchored at one end to a tab 48 turned up from shutter disc 38 toward diaphragm disc 20 and at its other end in a small hole 50 at the edge of dished section 22 of disc 20. Limit stops are provided for normally positioning shutter disc 38 so that a portion of said disc, between a pair of slots 40, overlies an exposure aperture 24 in alignment with lens aperture 18. These limit stops include tab 48 on shutter disc 38 adapted to engage a tab 52, turned up from diaphragm disc 20 toward disc 38, and thereby retain disc 38 against movement due to the bias of spring 46.

To move shutter disc 38 into a cocked position, the shutter disc is pivoted in a counterclockwise direction against the bias of spring 46 until a particular slot 40, which is normally positioned adjacent one side (the left viewing Fig. 2) of lens aperture 18, has moved across the lens aperture to the other side thereof. In order to prevent disc 38 from being pivoted too far in a counterclockwise direction so that another of slots 40 becomes aligned with lens aperture 18, there is provided a means for limiting the movement of said disc and, in the form shown, comprises a tab 54 turned up from shutter disc 38 toward diaphragm disc 20 and adapted to engage tab 52 on disc 20.

The shutter makes an exposure during the clockwise pivotal movement of the shutter disc under the bias of spring 46 from its cocked position to its original position of rest. The duration of the exposure, or the shutter speed, is dependent upon the length of the slot which crosses the lens aperture and the rotational speed of disc 38 due to the force exerted by spring 46, and may be varied by rotating shutter disc 38 in a counterclockwise direction so as to move a particular one of slots 40 into position to cross lens aperture 18 and admit light therethrough. Rotation of shutter disc 38 provides for different shutter speeds and is effected by rotation of diaphragm disc 20 in a counterclockwise direction so that tab 52 on disc 20 engages tab 48 on shutter disc 38 to pivot disc 38 together with spring 46 in a counterclockwise direction With disc 20.

Diaphragm disc 20 is provided with a plurality of numbers inscribed on its peripheral portion which extends exteriorly of housing 10, one number being associated with each exposure aperture 24 and representing a light value. The light values may preferably correspond to light value numbers carried on the scale of a conventional exposure meter, thus permitting setting of the shutter directly according to the prevailing light value number indicated on the exposure meter scale without the necessity of first computing a correct setting. Rotation of diaphragm disc 20 to bring a given number thereon into view exteriorly of the shutter housing sets up a correlated shutter speed and diaphragm aperture providing a predetermined exposure value. In the illustrated embodiment, for example, the shutter may be set for any of six exposure values, diaphragm disc 20 being provided with six exposure apertures with numbers 6 through 11 around its periphery and shutter disc 38 including six exposure slots 40. Assuming the lowest number to indicate a low light value, for a prevailing light value of low intensity, diaphragm disc 20 is set so that No. 6 is visible on the portion of said disc extending exteriorly of housing 10. Thus, the largest exposure aperture of disc 20 is positioned in alignment with lens aperture 18 and the longest exposure slot 40 of shutter disc 38 is positioned adjacent and to one side (the left viewing Fig. 2) of the exposure aperture. In one form of shutter, for example having a lens of relatively small aperture, diaphragm disc 20 is provided with two sets of three apertures, the apertures of each set being so formed as to provide for three full stop steps such as f/ 30, f/42 and f/ 60, and shutter disc 38 includes two sets of three slots, the slots in each set being of equal length. Each set of three slots in disc 38 is operatively associated with a set of three apertures in disc 20, the slots being so formed as to provide for exposures of l/25 of a second at f/30, f/42 and f/60, and 1/20() of a second at f/30, f/42 and f/ 60. By virtue of this arrangement, rotation of disc 20 through one full revolution is suflicient to set the shutter for any one of the series of six exposure values, each of which is one half the previous one.

As a means for pivoting shutter disc 38 into cocked position and covering the exposure aperture during pivotal movement of the disc, there is provided a cover blind or blade 56. Blade 56 is generally triangular in shape and includes a slot 58 mediate its ends and at which said blade is pivotally and slidably mounted adjacent shutter disc 38 on a hub 44 mounted on post 28 and retained thereon by a conventional retaining washer 60 and locking clip 62. The axis of slot 58 extends generally lengthwise of blade 56 and the center of post 28 is positioned to the left of lens aperture 18. Cover blind 56 includes a generally flat end section 64 positioned closely adjacent disc 38 and being enlarged so as to cover the lens aperture during pivotal movement of blade 56 during cocking of the shutter and a tapered end section 66. Blade 56 is normally retained in the position of rest covering lens aperture 18 by a coiled tension spring 68 secured at one end in a hole 70 in end section 66 and at its other end to a post 72 secured to rear housing portion 16.

Manually operable means, provided for pivoting blade 56 in a counterclockwise direction to cock and actuate the shutter, comprise a bell crank 76 having a central portion 78 at which it is pivotally mounted on a shaft 80 in turn pivotally mounted on a post 81 secured to rear housing portion 16, a manually engageable arm 82 extending exteriorly of the housing 10 through a slot formed therein, an actuating arm 84 extending from central portion 78 and a spacing washer 85 mounted on shaft 88 between crank '76 and housing portion 12. Crank 76 is biased in a clockwise direction by a tension spring 86 anchored at one end in bracket 74 and secured at its other end in an car 88 extending from central portion 78 of crank 76. An elongated connecting lever 90 is pivotally secured at one end to the end of arm 84 and includes a right angle end section 92 at which lever 90 is pivotally secured to enlarged end section 64 of cover blind 56 at a point :to the right (viewing Fig. 2) of the axis of slot 58 and the center of lens aperture 18. To actuate the shutter, the operator grasps and moves the portion of arm 82 extending exteriorly of the housing to the right to pivot crank 76 in a counterclockwise direction, this movement being transmitted through connecting lever 90 pivoting blade 56 in a counterclockwise direction.

To pivot shutter disc 38 in a counterclockwise direction into cocked position, end section 64 of cover blind 56 is provided with a tab 94 turned in from its end toward the rear of the shutter disc 38. Shutter disc 38 includes a plurality of ratchet-like shouldered portions 96 uniformly spaced around its periphery and adapted to be engaged by tab 94 during pivotal movement of blade 5-6 in a counterclockwise direction. Disc 38 includes one shoulder 96 for each exposure slot 40, each shoulder being so positioned as to be engaged by tab 94 when the slot 40, associated with the shoulder, is in position (at the left of the lens aperture) for making an exposure.

As cover blind 56 is pivoted in a counterclockwise direction, tab 94 engages ashoulder 96, pivoting shutter disc 38 so that an exposure slot 46, together with end section 64 of blind 56, is moved to the right past lens aperture 18 into cocked position. When disc 38 reaches this predetermined cocked position, blade 56 moves in a linear direction parallel to the axis of slot 58 so that tab 94 is disengaged from the shoulder 96, releasing shutter disc 38 for pivotal movement in a clockwise direction under the bias of spring 46. To insure the rapid linear movement of blade 56 parallel to the axis of slot 53 at the proper moment during its pivotal movement, there is provideda coiled hairpin-type spring 98 having elongated ends, one of which is anchored in end section 66 of cover blind 56 at hole 7.0 and the other of which is anchored to a post 109 secured to rear housing portion 16. During movement of disc 38 into cocked position, cover blind S6 is urged upward (viewing Fig. 2) by lever 90* so that tab 94 is held in engagement with a shoulder 96. Cover blind 56 is pivoted, for example, through approximately 45 during cocking movement of shutter disc 38 so that at cocked position, the upward force exerted on blade 56 is no longer sufficient to prevent the linear movement of blade 56 under the bias of both-springs 68 and 98, the effectiveness of which is increased as cover blind 56 is rotated. The point in the rotation of blade 56 at which linear movement and release of the shutter disc occurs is dependent upon the strength of springs 68 and'98, their positions and the direction of force exerted thereby. The release of shutter disc 33-for rotation under the bias of spring 46 is adapted to occur as end section 64 of cover blind 56 is pivoted out of alignment with the lens aperture and said aperture is uncovered. It is during the clockwise rotation of disc 38 that a slot 40 crosses the lens aperture to make an exposure, and upon release of crank 76, cover blind 56 returns to its original position of rest due to the bias of spring 68 andcrank 76-returns under the bias of spring '86.

Means are provided for completing an electrical circuit to a photofiash lamp (not shown) in synchronism with the operation of the shutter mechanism'and, in the form shown, comprises a resilient conducting arm 102 mounted at one end on an insulating member 104 secured to rear housing portion 16. Arm 102 is insulated from the remainder of the shutter mechanism and is connected with one terminal of a conventional receptacle or plug 106 secured to insulating member 104. The other terminal of plug 106 is grounded in the shutter housing together with connecting lever 96, and to insure a low resistance circuit through lever 90, the latter is connected to the grounded terminal of plug 1% by a lead wire 108. Conducting =arm 102 is so positioned with respect to connecting lever 96 that the end of lever 99 contacts the free end of arm 162, completing a photoflash circuit when cover blind 56, together with lever 90 secured thereto, moves linearly parallel to the axis of slot 58 (generally to the right) at the moment of release of shutter disc 38 for rotation. To provide for optimum contact between lever 94} and arm 162, a flange 93 may be formed turned up from the end of lever 90 and adapted to make contact with conducting arm 102 to complete the circuit.

The shutter includes means for holding an exposure slot 40 in shutter disc 38 in an aperture-uncovering position during time exposures and, in the form shown in Figs. 2 and 5, comprises an L-shaped section 110 of detent spring 34 having a short dependent end section 112 adapted to engage shoulders 96 and thereby retain shutter disc 33 in a position with a slot 40 in alignment with the lens aperture. As a means for positioning end section 112 for engagement with a shoulder 96, shaft 86, pivotally mounted on post 81, includes a cam portion 114 positioned to engage and deform L-shaped section 1100f detent spring 34. Section 110 is normally so biased as to urge end section 112 toward shutter disc 38, cam portion 114 being pivotable into an instantaneous exposure position wherein it deforms section 110 so as to hold end section 112 out of engagement with shutter disc,38, and is pivotable into a bulb or time exposure position wherein it is out of engagement with section 110 of the detent spring and permits end section 112 to move toward shutter disc 38. A manually engageable knob 116 extending exteriorly of front housing portion 12 may be secured to shaft for manually rotating said shaft and said cam section from one position to the other. In operation, in order to make a time exposure, cam section 114 is pivoted in a clockwise direction to the position shown in Fig. 2 allowing end section 112 to move into a position closely adjacent or in contact with the periphery of shutter disc 33. The shutter may then be cocked and actuated as previously described, and during the clockwise movement of the shutter disc a shoulder 96 is engaged by end section 112, thereby retaining a shutter slot 40 in alignment with the lens aperture. The duration of the time exposure is determined by the interval during which the operator holds cover blind 56 at its aperture-uncovering position and may be terminated by releasing actuating crank 76 to allow cover blind 56 to return to an aperture-covering position. The shutter remains set for time exposure and subsequent time exposures are effected in the same manner until cam section 114 is pivoted counterclockwise approximately to an inoperable or instantaneous exposure position to withdraw spring 34 from engagement with a shoulder 96. A pair of pins 118 may be provided secured to rear housing portion 16 for limiting the pivotal movement of cam section 114. Suitable means may also be provided in association with cam section 11 4 and cooperating with crank 76 for automatically returning end section 112 of spring 34 to instantaneous exposure position following each time exposure. In addition, it is apparent that satisfactory time exposures can best be made using an exposure slot 40 which is longer than the diameter of the exposure aperture and in a shutter wherein disc 33 includes exposure slots of shorter length, means, such as a cam secured to diaphragm disc 20 and adapted to engage and retain end 112 of spring 34 out of engagement with shutter disc 38, may be provided. In a like manner, means such as an electrically insulated cam secured to disc 2t) may be provided for engaging and deforming conducting arm 102 so that the flash circuit cannot be completed unless one of certain exposure slots 40, which are so formed as to provide an exposure in synchronism with the peak illumination of the flash lamp, is in position to provide the exposure.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A shutter for photographic apparatus comprising, in combination, means defining an exposure aperture, a shutter element mounted for movement between at least a pair of aperture-covering positions, said aperture being uncovered by said element during said movement, blade means mounted for movement along a first path between a first position wherein said blade means covers said aperture and a second position wherein said blade means uncovers said aperture, said blade means being also movable along a second path at an angle to said first path when in said second position, said blade means being releasably engageable with said shutter element for mov ing the latter from one of said aperture-covering positions to the other of said aperture-covering positions during movement of said blade means from said first position to said second position, means for moving said blade means from said first position to said second position,

and means for moving said blade means along said second path out of engagement with said shutter element for releasing the latter for movement from said other to said one of said aperture-covering positions to effect exposure.

2. A shutter for photographic apparatus comprising, in combination, means defining an exposure aperture, a shutter element having at least one opening therein and being normally mounted in aperture-covering position wherein said opening is to one side of said aperture, said element being movable between said aperture-covering position and a displaced position, said opening being movable in and out of coincidence with said aperture during movement of said element between said positions, a cover member mounted for rotation between a first position wherein said member covers said aperture and a second position wherein said member uncovers said aperture, said cover member being movable in a direction generally perpendicular to its axis of rotation when in said second position, means for rotating said cover member in a first direction from said first to said second position, means comprising a portion of said cover member and being engageable with said shutter element for moving said element from its apenture-covering position to its displaced position during rotation of said cover member in said first direction, means for efiecting the movement of said member in said plane when in said second position for disengaging said shutter element, and means for moving the disengaged element from said displaced position to said aperture-covering position while said member is in said second position, thereby efiecting an exposure through the coincident aperture and opening.

3. A shutter for photographic apparatus comprising, in combination, housing means having an aperture formed therein, a shutter element mounted on said housing for rotary movement relative to said aperture between a predetermined pair of a plurality of aperture-covering positions, said shutter element being in uncovering relation to said aperture during a portion of said movement between said pair of aperture-covering positions, a cover member mounted for rotary movement between a first position wherein said member covers said aperture and a second position wherein said member uncovers said aperture, said cover member being movable in a plane in a direction generally perpendicular to its axis of rotation, means for rotating said cover member from said first to said second position, means comprising a portion of said cover member and being engageable with said shutter element for moving the latter from one of said pair of aperture-covering positions to the other of said pair of aperture-covering positions during movement of said cover member from said first to said second positions, said cover member being disengageable from said shutter element by movement of said member in said plane in said direction generally perpendicular to its axis of rotation, means for moving said member in said plane when in said second position for disengaging said shutter element, and means for moving the disengaged shutter element from said other of said pair .of aperture-covering positions to said one of said pair of aperture-covering positions, thereby effecting an exposure.

4. A shutter for photographic apparatus comprising, in combination, means defining an exposure aperture, a shutter element mounted for movement in a predetermined direction for uncovering said aperture, a cover member mounted for rotary movement between a first position wherein said member covers said aperture and a second position wherein said member uncovers said aperture, said cover member being releasably engageable with said shutter element for moving the latter in a direction opposite to said predetermined direction, said cover member being mounted for linear movement in a direction substantially perpendicular to its axis of rotation when in said second position, said cover member being disengageable from said shutter element by said linear movement of said member, means for rotating said cover member from said first to said second position for engaging and moving said shutter element, means for effecting said linear movement of said cover element for disengaging said shutter element, and means for moving the disengaged shutter element in said predetermined direction so as to uncover said aperture and efiect exposure therethrough.

5. A shutter for photographic apparatus as defined in claim 4 wherein said shutter element has a plurality of openings therein and is normally mounted in covering relation to said aperture with a predetermined one of said openings positioned to one side of said aperture, said shutter element being movable so that said one of said openings is movable across said exposure aperture for uncovering the latter, said cover member being in covering relation to said aperture during movement of said opening across said aperture in said opposite direction.

6. A shutter for photographic apparatus as defined in claim 5 including means engageable with said shutter element for moving the latter to position one of said openings to one side of said aperture.

7. A shutter for photographic apparatus as defined in claim 4 wherein said shutter element includes a plurality of slots of different lengths formed therein, said shutter element being mounted for rotation between at least one of a plurality of first aperture-covering positions wherein a predetermined one of said slots is located to one side of said exposure aperture and at least a corresponding one of a plurality of second aperture-covering positions wherein said one slot is located to the other side of said exposure aperture, said slot being movable across said aperture to provide for an uncovered exposure aperture during rotation of said shutter element, the time interval during which said aperture is uncovered by said slot being a function of the dimensions of the latter, said cover member being in covering relation to said aperture during movement of said slot from a first to a second aperturecovering position and being in said second position during movement of said slot from a second to a first aperturecovering position.

8. A shutter for photographic apparatus comprising, in combination, a housing having an aperture formed therein, pivot means mounted within said housing, aperture control means mounted for rotary movement on said pivot means, a shutter element mounted on said pivot means for rotary movement relative to said housing and said aperture control means, said shutter element providing a closure for said aperture when at a stationary position and providing for an open aperture during return movement from a displaced position to said stationary position, spring means mounted between and cooperating with said aperture control means and said shutter element for causing the return movement of the latter to said stationary position from said displaced position, means comprising portions of said aperture control means for altering the stationary position of said shutter element during rotation of said aperture control means and for limiting the rotary movement of said shutter element relative to said aperture control means, a cover blade having a slot intermediate its ends and extending generally longitudinally thereof, said blade being mounted at said slot on said pivot means for rotary movement about said pivot means and linear movement in the direction of said slot, said blade having an end section providing a closure for said aperture when at a stationary position and being pivotable to a displaced position wherein said aperture is uncovered, means for pivoting said cover blade to an aperture-uncovering position, means comprising a portion of said cover blade for engaging and rotating said shutter element to a displaced position during rotary movement of said cover blade to aperture-uncovering position, and spring means so disposed as to exert force on said blade in a direction generally parallel to the direction of said slot when said blade is in apertureuncovering position to efiect the linear movement of said I blade in the direction of said slot to disengage said shutter element and release the latter for return movement to said stationary position.

9. A shutter for photographic apparatus comprising, in combination, a housing having an aperture formed therein, pivot means mounted within said housing, aperture control means mounted for rotary movement on said pivot means, a shutter element mounted on said pivot means for rotary movement relative to said housing and said aperture control means, said shutter element providing a closure for said aperture when at a stationary position and providing for an open aperture during return movement from a displaced position to said stationary position, spring means mounted between and cooperating with said aperture control means and said shutter element for causing the return movement of the latter to said stationary position from said displaced position, means comprising portions of said aperture control means for altering the stationary position of said shutter element during rotation of said aperture control means and for limiting the rotary movement of said shutter element relative to said aperture control means, a cover blade having a slot intermediate its ends and extending generally longitudinally thereof, said blade being mounted at said slot on said pivot means for rotary movement about said pivot means and linear movement in the direction of said slot, said blade having an end section providing a closure for said aperture when at a stationary position and being pivotable to a displaced position wherein said aperture is uncovered, means for pivoting said cover blade to an aperture-uncovering position, means comprising a portion of said cover blade for engaging and rotating said shutter element to a displaced position during rotary movement of said cover blade to aperture-uncovering position, and means for eifecting the linear movement of said blade in the direction of said slot when said blade is in aperture-uncovering position to disengage said shutter element and release the latter for return movement to said stationary position.

10. A shutter for photographic apparatus comprising, in combination, a housing having an aperture formed therein, a shutter element mounted on said housing for rotary movement relative to said housing, said shutter element providing a closure for said aperture when at a stationary position and providing for an open aperture during movement between a displaced position and said stationary position, spring means mounted on said housing and cooperating with said shutter element for causing a return movement of the latter to said stationary position from said displaced position, means for providing a plurality of stationary positions of said shutter element during rotation of said means and for limiting the rotary movement of said shutter element relative to said means, a cover blade having a slot intermediate its ends and extending generally longitudinally thereof, said blade being mounted at said slot for both rotary movement and linear movement in the direction of said slot, said blade having an end section providing a closure for said aperture when at a stationary position and being pivotable to a displaced position wherein said aperture is uncovered, a manually operable crank, a connecting lever pivotally secured at one end to said crank and at its other end to said blade, said lever being so disposed as to impart a rotary aperture-uncovering movement to said cover blade, means comprising a portion of said cover blade for engaging and rotating said shutter element during rotary movement of said cover blade to aperturenncovering position, and spring means so disposed as to exert a force on said blade in a direction generally parallel to the direction of said slot when said blade is in aperture-uncovering position to effect the linear movement of said blade in the direction of said slot to disengage said shutter element and release the latter for return movement to said stationary position.

11. A shutter for photographic apparatus comprising, in combination, a housing having an aperture formed therein, pivot means mounted within said housing, aperture control means mounted for rotary movement on said pivot means, a shutter element mounted on said pivot means for rotary movement relative to said housing and said aperture control means, said shutter element providing a closure for said aperture when at a stationary position and providing for an open aperture during return movement from a displaced position to said stationary position, spring means mounted between and cooperating with said aperture control means and said shutter element for causing the return movement of the latter to said stationary position from said displaced position, means comprising portions of said aperture control means for altering the stationary position of said shutter element during rotation of said aperture control means and for limiting the rotary movement of said shutter element relative to said aperture control means, a cover blade having a slot intermediate its ends and extending generally longitudinally thereof, said blade being mounted at said slot on said pivot means for rotary movement about said pivot means and linear movement in the direction of said slot, said blade having an end section providing a closure for said aperture when at a stationary position and being pivotable to a displaced position wherein said aperture is uncovered, a manually operable connecting lever secured at one end to said blade and being so mounted as to impart rotary aperture-uncovering movement to said blade, means comprising a portion of said blade for engaging and rotating said shutter element to a displaced position during rotary movement of said cover blade to aperture-uncovering position, said connecting lever being so disposed as to exert a force on said blade in a direction generally parallel to the direction of said slot when said blade is in apertureuncovering position to efiect the linear movement of said blade in the direction of said slot for disengaging said shutter element and releasing the latter for return movement to said stationary position.

12. A shutter for photographic apparatus comprising, in combination, a housing having an aperture formed therein, pivot means mounted within said housing, aperture control means mounted for rotary movement on said pivot means, a shutter element mounted on said pivot means for rotary movement relative to said housing and said aperture control means, said shutter element providing a closure for said aperture when at a stationary position and providing for an open aperture during return movement from a displaced position to said stationary position, spring means mounted between and cooperating with said aperture control means and said shutter element for causing the return movement of the latter to said stationary position from said displaced position, means comprising portions of said aperture control means for altering the stationary position of said shutter element during rotation of said aperture control means and for limiting the rotary movement of said shutter element relative to said aperture control means, a cover blade having a slot intermediate its ends and extending generally longitudinally thereof, said blade being mounted at said slot on said pivot means for rotary movement about said pivot means and linear movement in the direction of said slot, said blade having an end section providing a closure for said aperture when at a stationary position and being pivotable to a displaced position wherein said aperture is uncovered, manually operable crank means pivotally mounted within said housing, a connecting lever pivotally secured at one end to said crank means and at its other end to said cover blade, said connecting lever being so mounted as to impart a rotary aperture-uncovering movement to said cover blade, means comprising a portion of said cover blade for engaging and rotating said shutter element to a displaced position during rotary movement of said cover blade to an aperture-imeovering position, said connecting lever being so disposed as to exert a force on said blade in a direction generally parallel to the direction of said slot when said blade is in aperture-uncovering position to efiect the linear movement of said blade in the direction of said slot so as to disengage said shutter element and release the latter for return movement to said stationary position.

References Cited in the file of this patent UNITED STATES PATENTS Hutchinson Dec. 6, 1949 Hume Ian. 3, 1950 Fuerst May 9, 1950 Aiken July 4, 1950 Wareham Mar. 24, 1959 

